Electric-current regulator



July 23, 1929. J. M. BOYKOW ELECTRIC CURRENT REGULATOR 2 Sheets-Shee t 1 Filed Nov. 1, 1926 July 23, 1929. J BOYKQW 1,721,853

ELECTRIC CURRENT REGULATOR Filed Nov. 1, 1926 2 Sheets-Sheet 2 Jnvenfor; flaw Mria, ,zgykov Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

J'OEANN MARIA BOYKOW, F BERLIN-LICHTERFELDE-WEST, GERMANY, ASSIGNOB TO IESSGEBATE BOYKOW G. M. B. 11., OF BEBLIN-LICHTEBFELDE-WEBT, GERMANY, A

GJBPORATION.

ELECTRIC-CURRENT REGULATOR Application filed November 1, 1926, Serial No. 145,681, and in Germany November 7, 1925.

My invention relates to im rovements in electric current regulators, an the object of the improvements is to provide a regulator by means of which the intensity of an electric current may be regulated proportionally to the number of revolutions per minute of a rotary member so that upon measurement of said current the speed of said member may be determined. With this object in view my invention consists in combining an element upon which is exerted a torque by mechanism driven by the shaft. whose speed is, to be measured, such element for example, comprising a cylinder made from electrically l conductive material and disposed within a rotary field of forces, generated by said mechanism, with a brake, the braking power of which is generated by the current to be regulated, the braking moment being made equal to the torque exerted on said element automatically by means of the apparatus itself, so that the element is forced to remain stationary, and the electric current producing the braking moment being proportional to the angular velocity of the said rotary field, when the braking moment and the torque on said element or cylinder are alike.

In order that my invention be more clearly understood an exam le embodying the same has been shown in t e accompanying drawings, in which the same reference characters have been used in all the views to indicate corresponding parts. In said drawings,

Fig. 1, is a sectional elevation showing my as improved apparatus,

ig. 2, is a detail view showing the braking coil and the switch controlled thereby for regulating the resistance regulating the intensit of t e current flowing through the 4.0 said coi and Fig. 3, is a diagram showing the electrical connections of the apparatus.

Inthe example shown in the figures, a shaft 2 rotated from a suitable source of energy at the desired velocity carries magnets 1. On a second shaft 3 a metallic cylinder 4 is mounted which is surrounded by a stationary cylinder 5 fixed to a head 45 secured to a casing 28, the object of the cylinder 5 being to prevent the air carried along by the magnets from acting on the cylinder 4 and affecting the moment thereof. Further, a coil 6 is carried by the shaft 3, which coil is located within a stationary magnetic field 7. Thus the coil 6 is rigidly connected with the cylinder 4.

At the end of the shaft 3 there is a switching apparatus S controlling electromagnets 8 and 9 of a reversing gearing W. The said reversing gearing is adapted to operate a current regulator R controlling the intensity of the current flowing through the coil 6.

The switching apparatus S, the reversing gearing W and the regulator R are constructed as follows: To the end of the shaft 3 a crank 46 is secured the pin 10 of which engages in the bifurcated bottom end of the lever 12 rockingly mounted on a fixed bolt 11 and carrying at its op osite end slide contacts 13 cooperating wit contact segments 14, 15 and 15'. According to the posit-ion of the coil 6 within the stationary magnetic field 7 current is supplied from a source 17 to the electromagnet 8 or 9. Between the said electromagnets there is.an armature 19 rockingly mounted at 18 which armature is forme with a bifurcated end 20, as is common with clutch levers of this type, engaging in an annular groove 21 of the hub of a pair of bevel gear wheels 22 and 22. The said gear wheels are continuously rotated in the same direction from a suitable source of power.

The gear wheels 22 and 22' cooperate with a bevel gear wheel 23 the shaft 24 of which carries a contact brush 25 in slidin enga ement with a segmental contact bar 2 and t e turns or taps of a rheostat. Upon energizing either one of the electromagnets 8 or 9 the gear wheel 23 is engaged byeither the gear wheel 22 or 22, respectively so that the brush 25 is turned in one or the other direction for increasing or reducing the resistance.

The rotar electromagnets 1 are energized by means of a source of electric current 29 through brushes 30 bearings on slide rings 31. The said slide rings 31 are electrically connected by rods 32 with rods 33 and 34 embedded in and insulated from the shaft 2. The rods 34 are connected by leads 35 with the coils 36 of the electromagnets 1.

The coils 37 of the stationary electroma nets 7 are connected in series with the coi s 36, so that the current intensit is the same in both coils, and the fields pro uced thereby are in a definite ratio. The current is supplied to the coil 6 through contact sprin 38 engaging contact pins 39 disposed coaxially of the shaft 3, and connected with the coil 6 by leads 40. The contact springs 38 are connected respectively with a source of electric energy 41 and the rheostat B, so that the source of electric energy 41, the coil 6 and the rheostat R are included in the same circuit.

The operation of the apparatus is as follows Let us assume that the electromagnets 1 are rotated, when looking from the side of the electromagnets 7, in clockwise direction. Thereby the coil 6 and the crank 46 are turned in the same direction, so that the pin 10 rocks the switch lever 12 and shifts the contacts 13 thereof in the opposite direction. Thus the contact segment 14 is electrically connected with the contact segment 15, and current is supplied from the source 17 over segments 14 and 15 to the coil of the electromagnet 9. The armature 19 is attracted by the electromagnet 9 and throws the bevel gear wheel 22 into engagement with the gear wheel 23, which is thereby rotated so as to rock the switch arm 25 in the direction of the arrow as shown in Fig. 3, thus reducing the resistance of the circuit of the coil 6, until the intensity of the current flowing through the said coil is such that the moment of the coil exceeds that of the metal cylinder 4. Thereafter the coil 6 and the switch arm 12 and the contacts 13 carried thereby are moved in the opposite direction. When making contact with the segments 15 the contacts 13 connect the electromagnet 8 with the source 17, whereupon the operation of the rheostat R is repeated in the reverse sense.

The operation is repeated until the moment of the coil 6 is equal to that of the cylinder 4, in which case the intensity of the current flowing through the coil 6 is proportional to the moment of the metal cylinder 4.

The moment of the metal cylinder 4 depends only on the angular velocity of the electromagnets 1 and that in a higher degree the smaller the temperature coefiicient of the metal of the cylinder at is. Thus the intensity of the current flowing through the coil 6 is proportional to the angular velocity of the magnetic system 1.

The apparatus can be used for various purposes where it is desired to control a current in dependence on the rotary speed of an obect. For example, the apparatus can be used in connection with measuring instruments for generating a moment correspondi'ng to a certain number of revolutions, at a place located at a distance from the apparatus. By means of the apparatus I am enabled directly to measure velocities, to make long distance indications, etc.

Where in the claims I employ the term loose coupling it will be understood that I include thereby such couplings as have a driv ng element and a driven element but no rlg d connection between the two, so that the driven element maybe maintained stat'ronary relatively to said driving element by means of an opposing force.

While in describing the invention referonce has been made to a particular example embodying the same I wish it to be understood that my invention is not nmitedto the construction shown in the drawings, and that various changes may be made in the general arrangement of the apparatus and the construction of its parts without departing from the invention.

I claim:

1. An apparatus for regulating electric current intensities proportionally to a number of revolutions per minute, comprising a loose coupling having a rotary driving member and a driven member, an electric brake connected with said driven member, and means controlled by the driven member for regulatingv the current of said electric brake so that the moment of the brake is equal to that of the coupling.

2. An apparatus for regulating electric current intensities proportionally to a number of revolutions per minute, comprising a loose coupling having a rotary magnetic driving member, and a rotary metal cylinder within the magnetic field of said driving member, an electrio bralge connected with said driven member, and -means controlled by the driven member for regulating the current of said electric brake so that the moment of the brake is equal to that of the coupling.

3. An apparatus for regulating electric current intensities proportionally to a number of revolutions per minute, comprising a loose coupling having a rotary magnetic driving member, a rotary metal cylinder within the magnetic field of said driving member and a cylindrical member between said driving member and metallic cylinder, an electric brake connected with said driven member, and means controlled by the driven member for regulating the current of said electric brake so that the moment of the brake is equal to that of the coupling.

4. An apparatus for regulating electric current intensities proportionally to a number of revolutions per minute, comprising a loose coupling having a rotary drivlng member and a driven member, an electric brake connected with said driven member comprising a stationary magnetic member and an electric coil connected with said driven member and included in the circuit the current intensity of which is to be regulated, and an electric switch apparatusconnected with said coil for varying the intensity of the current flowing through said circuit.

5. An apparatus for regulating electric current intensities proportionally to a number of revolutions per minute, comprising a loose coupling having a rotary driving member and a driven member, an electric brake connected with said driven member comprising a stationary ma etic member and an electric coil connecte with said driven member and included in the circuit the current intensity of which is to be regulated, and an electric switch apparatus connected with said coil and comprising a rheostat included in the circuit of said coil, electric regulatin means for said rheostat, and a switch contro ling said re ulating means.

6. The method 0 measuring the speed of a rotating body which comprises creating a rotating magnetic field whose speedis proplortional to the speed of said body and proucing a torque on a conducting element positioned in said field, counteracting said torque with an opposing force so as to maintain said element in normal position, and measuring said force.

7. The method of measuring the speed of a rotating body which comprises creating a rotating magnetic field whose speed is proportional to the speed of said body and producing a torque on a conducting element positioned in said field, counteracting said torque with an equivalent torque produced by an opposing regulatable magnetic field, and measuring the current required to maintain said last mentioned magnetic field.

8. An apparatus for regulating an electric current proportionally to the speed of a rotating body, comprising a loose coupling having a rotary drivin member and a driven member, an electric rake connected with said driven member and including an electric coil traversed by a re ulatable current, and a rheostat controlle by said driven -member and included in the circuit of said coil, whereby the strength of the said current is proportioned to the braking force necessary to balance the torque on said driven member.

In testimony whereof I have aflixed my signature.

J OHANN MARIA BOYKOW. 

